1. Field of the Invention
The present invention relates to a programmable interface designed for the reception, on N input ports, of information elements coming from N distinct information transmission input carriers or media, or coming from one and the same carrier or medium with N distinct inputs.
The invention can be applied in an especially advantageous way in the field of computerized domestic applications involving the management of information for domestic installations.
2. Description of the Prior Art
Known devices for computerized domestic applications generally use five (or even more) distinct types of media for the transmission of information, enabling the devices to be supplied with the information elements that come from the various appliances of the domestic installation to be managed, and that are likely to modify their state of operation, namely turning-on, turning-off etc. These five types of information transmission media include carrier current, twisted pairs, infra-red radiation, coaxial cables and RF links. They may also extend to optical fibers, ultrasonic transmission and other types of media.
For each information transmission medium, the digitized information elements come in the form of words including a succession of bits, the duration of which depends on the medium considered. For example, for transmission by carrier current which is relatively sensitive to noise, the duration of a bit may be 416 .mu.s (which corresponds to 2400 bauds) or 832 .mu.s (which corresponds to 1200 bauds, a value that will become even greater in the future) whereas, for the other information transmission media which are less sensitive to noise, the duration may be of the order of 104 .mu.s or even less (9600 bauds to 1 megabit for twisted pairs or optical fibers).
Furthermore, the working of these known devices generally includes the use of five input bit controllers, the function of which is to ensure that the digitized information elements received by a given information medium include bits whose duration corresponds to the characteristic bit duration for the medium considered. In practice, such bit controllers are usually made in wired logic form and, in a predetermined or fixed mode of operation, their triggering occurs on the rising or descending edge of the signal, the complementary edge being detected through an observation window opened around the expected position for the complementary edge.
The known devices that have just been described therefore all include the drawback of requiring a bit controller for each type of information transmission medium, thus considerably adding to the complexity of their construction.
Hence, the technical problem to be resolved by the present invention is that of providing a programmable interface, in accordance with the introduction, which would enable the use of a single bit controller for, at least, the N information transmission input media.